10 
WOUNDS PENETRATING INTO THE CHEST. 
blood ; and next, because the blood from the jugular, before 
being transferred into the chest, had remained for a certain time 
in contact with bodies foreign to the animal, and by means of 
this had already lost a portion of its life. 
The alteration of the blood was, besides, regulated by the 
duration of the communication of air with the cavity of the 
chest. The general and local phenomena which the animals 
subjected to these experiments presented, were very analogous 
to those in the horses on which the first experiments had been 
made. 
The only particular which it is necessary to mention, with 
regard to the variety of experiments related in this section, has 
reference to the quantity of blood thrown into the chest. In all 
our experiments we injected at least six pounds of venous blood. 
It results from this, that the clots of blood are large, and are 
less promptly changed by contact with the air; but notwith¬ 
standing this, we have found that the influence of the air is 
most strongly marked, and at the end of three days only, the 
clot (which was probably formed at the first) becomes liquefied, 
and in part mingled with the pleural serosity. 
We cannot speak of the changes effected in the blood in a 
less time than two days; for as to all the horses that we opened 
three days, or a little less, had expired after the injection of the 
blood ; and most of them died in consequence of our experi¬ 
ment. We could retard their death at our pleasure, by cutting 
off the communication of the air with the chest from time to 
time ; but if that communication was constant, or through the 
medium of a large opening, the death of the animal was pro- 
portionably hastened. 
9. Simple tvoimds, with injection of hlood drawn from the 
jugular a certain time before, and without the introduction of air. 
When the blood is not injected as soon as it is drawn from 
the vein, it speedily loses certain of its properties, or, if we may 
so express ourselves, a portion of its life ; or, at least, it acts 
more as a foreign body when it is introduced into the chest. 
The symptoms and the result approach nearly to that which we 
have just described, when we had injected blood as soon as it 
was drawn from the jugular, and had left a communication be¬ 
tween the pleural cavity and the atmosphere: nevertheless, we 
remarked that the animals survived longer after the injection : 
this would be probable, considering that the interior of the 
chest was not in communication with the atmosphere. The clot 
of blood was more slowly decomposed, and the respiration was 
not so much disturbed during the few first days after the 
operation. The time, however, always arrived when the blood 
